During the operating life of an absorption chiller, any introduction of air into the system will result in oxidation of the metal surfaces and this in turn leads to further depletion of the corrosion inhibitors in the aqueous salt solution, and ultimately the rust scale (iron oxide) will dislodge and find its way into the shell side of the heat exchanger and be introduced to the spray nozzle lines, plugging the nozzles.
Present service procedures require periodic shut-downs of the system for cleaning, which involves disconnections, partial dismantling, etc., all increasing the chances of air entering the system. The present invention overcomes these obstacles by the provision of means for automatically filtering the aqueous salt solution, particularly in systems using lithium bromide. This can be achieved without adversely effecting the operation of the chiller or requiring complicated and costly changes in the system. Accordingly it is a principal object of the invention to introduce a liquid-transfer unit including a magnetic filter and associated pump between the concentrated salt solution line and the intermediate solution line (or less concentrated solution line), the purpose being to filter out rust particles from the circuit. To augment this process, a pneumatic vibrator or the like is added to the heat exchanger upstream of the magnetic filter unit in order to increase the rust-removing function of that unit.
A further object is to provide a scavenging unit between the refrigerant line and the diluted salt solution line and the refrigerant line for the purpose of removing excess ammonia In the case of each of the liquid-transfer units (magnetic and scavenging), a pump is utilized in addition to and independently of the typical system pumps.
Features and advantages of the invention, additional to those just outlined, will appear as a preferred embodiment of the invention is disclosed in the detail in the ensuing description in conjunction with the accompanying drawings.